1. Field of the Invention
The invention relates to diagnostic devices used to measure luminance, chromaticity and sound. Specifically, this invention relates to local and remote monitoring of luminance, chromaticity, sound, infrared illumination and/or synchronization of the image and sound thereof.
2. Background of the Invention
Presently, there are devices and methods that when individually combined may be used to measure and adjust the luminance levels on a display surface, such as, but not limited to, a cinema screen, and to measure the sound quality within the same display area.
One device that measures luminance (brightness of the screen image), low or imperceptible variations in the luminance of a display surface such as a movie screen (otherwise known as “flicker”), and the amount of horizontal and vertical motion of an image that is being displayed on the screen (known respectively as “weave” and “jump” of the image) is set forth in U.S. Pat. No. 5,818,597 issued to Ultra Stereo Labs, Inc. entitled PROJECTION SYSTEM ANALYZER. However, in order to monitor the accompanying sound within the same display area such as a theater or auditorium, a microphone also must be mounted somewhere within the display area and the signal therefrom processed to determine whether the sound in the display area meets standard industry levels, such as those created by the Society of Motion Picture and Television Engineers (“SMPTE”), or levels desired by the user.
With the transition of theaters from film to digital media, some theaters have instituted Network Operations Centers (hereafter, “NOC”) from which the equipment in each theater in the network can be monitored and controlled from one or more locations. Some theaters may use commercially available internet cameras to monitor the sound and luminance within a theater. For example, an internet camera, which is capable of transmitting sound as well as images, may be aimed at a theater screen to monitor the sound and the images as they are seen and heard by an audience. At the same time that the images are being seen and the audio is being heard by the audience, they also may be transmitted by the camera to the NOC via the internet. NOC personnel then may monitor the audiovisual feeds from the camera(s) to determine whether the audiovisual equipment in the theater is working properly and to ensure that there has been no degradation in the audiovisual display in the theater. This method of monitoring the screen luminance and the sound within the theater is subjective as it is dependent upon the knowledge and skill of the person monitoring the feed from each camera.
Further, when using internet cameras, it may be difficult to fine-tune the theater projector and sound equipment (including each individual speaker) to ensure that they are working at optimal values. By way of example and not limitation, some internet cameras may have wide angle lenses which are not suitable for making suitable luminance measurements. Also, because some internet cameras have built-in automatic gain control circuitry to optimize the picture and the sound transmitted therefrom, it may be difficult to obtain accurate readings of what is actually being viewed and heard from within the theater. Thus, it may be difficult to meet the uniform professional standards for luminance and sound solely using internet cameras. Further, because the internet camera signals may be transmitting their output to the NOC over the internet, there may be a risk that the camera signals may be intercepted by unauthorized persons, so that there is a possibility of piracy of the images and sound being transmitted by the camera.
Some theaters may use professional light measurement instruments, wherein a technician uses a professional spotmeter to measure the luminance on a precise area on a screen. During the measurement process, the projection equipment may be continuously adjusted until the optimal luminance on the screen being tested is achieved. A similar method may be performed by a technician using professional sound meters that take sound measurements in order to determine whether the sound system and each of the speakers located within a theater are operating within the normal optimal operating range. Using this process to monitor and measure the luminance and sound in a theater requires the presence of a technician who goes from theater to theater to constantly measure and monitor the equipment.
Thus, there is need for a device that can remotely monitor the luminance, chromaticity and infrared display surface illumination and the sound heard within the display area to detect any changes thereto so as to determine when and whether the equipment is operating properly so to decide whether maintenance of the display and sound equipment is required. This would be of great use in the art, as it would conserve resources by requiring less technician time to monitor and maintain the sound and video quality. It also would be of great benefit as it would give rapid notification of any changes or degradation in the outputs of the sound and projection equipment so that they can be quickly and precisely addressed and corrected. In addition, it also would be of great use in the art if the device also could provide remote synchronization verification to ensure that the video signal is synchronized with its audio signal. It further would be of great advantage to the art if the monitoring equipment also could detect whether any closed captioning, assisted listening and visual narrative (e.g. Americans with Disabilities Act (“ADA”)) equipment is transmitting properly. Further, it would be of great benefit to the art if the monitoring and testing equipment were located within a single package that could be easily mounted in a location that is unobtrusive and essentially tamperproof.